1. Field of the Invention
Temperatures below zero cause problems in the operation of diesel engines because they tend to cause wax formations in the fuel for the engine. The flaky wax formations tend to clog the filters in the fuel flow system and prevent proper operation of the engine. To overcome this problem, it is necessary to preheat the fuel before it is applied to the engine in order to avoid clogging of the filter system.
2. Prior Art
Previous pre-heaters have used hot water in the radiator of the vehicle. In one such heater, the fuel line was passed through an outer larger conduit which jacketed the inner conduit. The hot water in the outer conduit heated the fuel in the fuel line as it passed therethrough. In these heaters, the fuel remained in its original line, which was relatively small in diameter and therefore did not become adequately heated.
In a copending application of the same inventor and assigned to the same assignee as the present invention entitled "A Heater for Pre-Heating Fuel", Ser. No. 967,523, filed Dec. 7, 1978, now U.S. Pat. No. 4,208,996, there is described another type of pre-heater which is generally cubical in shape and divided into two separate chambers, with heated water in one chamber and the fuel in the other. This provided a greater area for the fuel to be heated.
While the pre-heater described in the aforementioned application offered advantages over the prior art, it was found that by changing the physical structure of the pre-heater from substantially rectangular enclosures to cylindrical enclosures and providing a special type of heat transmitting member between the water and the fuel that a more commercially acceptable heater of higher efficiency could be made. It is desirable that such cylindrical enclosures that sealing of the parts involved by welding provide maximum protection against leakage of either the fuel or hot water be provided and that the areas for welding be readily accessible.